Washington County is a county in the U.S. state of Idaho. As of the 2010 census, the population was 10,198. The county seat and largest city is Weiser, with over half of the county's population. The county was established in 1879 when Idaho was a territory and named after U.S. president George Washington.
Equine Gestation. Miniature ponies, and all other breeds of horses, typically carry their foals for approximately 11 months. The average miniature horse mare will carry her foal for around 330 days before giving birth. The actual length of pregnancy can vary between 320 days and 380 days.
Quick Answer. The standard mare gestation length is from 320 to 362 days after the date of breeding, and on average, most mares will foal, or give birth, 330 to 345 days after a successful breeding. However, it is common for a mare to successfully give birth in a later period than the average range. Keep Learning.